Secondary Menu

Control RGB LEDs With the Wave of Your Hand.

About: TangibleTec helps you bring your ideas to life. Draw on our experience in Mechanical, Electrical, and Software Engineering to provide you with the concept, design, or product you need to make your idea a rea...
More About TangibleTec »

Introduction

We were invited to help out at our local elementary school's STEM night, and needed a cool demonstration, with little time to prepare.

So, we looked through the tech we had laying around, and came up with the idea of using the LeapMotion hand tracking sensor, to control the color and intensity of RGB lights.

There is no better way to get kids excited about science, technology, engineering, and math, than having a fun and interactive hands on example.

Note: The following lists are parts closest to what we used for our setup.

Attachments

Step 2: Building the LED Controller

To control a 12V RGB LED strip with an Arduino, we will need to build a simple circuit.

Lucky for us, this can be accomplished with a single chip, the ULN2803. (datasheet)We don't need to add any resistors, since our RGB LED strip already has them built in.

We'll need to supply 12V to pins 9 and 10.

Pin 9 - GND, 12V negative side

Pin 10 - 12V positive side

Also, be sure to tie the ULN2803 chip's and the Arduino's grounds together.

Then pins 1-8 can be used as PWM inputs from an arduino, and pins 11-18 can be used as the common sink for your 12V - 30V device.

OPTION 1: Using a Breadboard

Most RGB LED light strips have a header that can be directly plugged into a breadboard.

Follow the wiring diagram above.

Tools Needed

Breadboard

Jumper wires

OPTION 2: Building an arduino shield

A protoboard can be used to create a robust, and permanent arduino shield.This is what we did, except we used a scrap xbee shield we picked up from Sparkfun.The wiring diagram above shows how this can be done.

Tools Needed

Soldering Iron + Solder

Wire

Wire Strippers

Tips:

You may have noticed that we are only using 3 pins out of the 8 available.To make more use of the chip, you could drive two RGB LED strips at once.Or, If you need to drive a device with a little more current, then you can double up pins (run in parallel).